Attachment for dental engines.



R. L. SPAULDING.

ATTACHMENT FOR DENTAL ENGINES.

APPLICATION FILED APR. 14 I917.

Patented June 4, 1918.

. ROY L. SPAULDING, or HELENA, MONT NA.

ATTACHMENT non DENTAL ENGINES.

Specification of Letters Patent.

Patented June 41, 1918.

Application filed'April 14, 1917. SerialNo. 162,031.

Helena, in the county of Lewis and Clark and State of Montana, have invented certain new and useful Improvements in Attachments for Dental Engines; and I do hereby declare the following to be a full, clear, and exact description of the invention, such aswill enable others skilled in the art to which it appertains to make and use the same. l

My invention relates to an improved attachment for dental engines, and more par ticularly to a mandrel for holding spiral or other broaches or small reaming instruments used in opening and cleaning'the canals of teeth and which is capable of efiicient use in connection with straight or any angle dental engine hand piece.

One of the aims of this invention is to provide a mandrel whereby the breach or other instrument is inserted through the mandrel from its inner end in a manner that the operating end of the instrument may be projected at any desired distance from its other end and secured in the latter end in an efficient manner but not sufficiently rigid to prevent the instrument from rotating in the mandrel should the instrument encounter an obstruction suiiicient to break the instrument OH in the tooth, which accident often happens when the instrument is rigidly secured in the hand piece as is now the common practice.

With these objects in view, the invention consists in the improved construction, arrangement, and combination of parts hereinafter fully described, and afterward specifically claimed.

In order that the construction and operation thereof may be readily comprehended, an approved embodiment of the invention is illustrated in the accompanying drawings, and will be fully described, having reference to said drawings, in which- Figure 1 is a side elevation of the invention.

Fig. 2 is a similar view to Fig. 1, excepting the compression nut is shown in section.

Fig. 3 is an end view of the device.

Fig. 4 is an end view of the mandrel with the compression nut removed.

Fig. 5 is a fragmentary side elevation of the inner end of the mandrel showing the same asturn ed to a position at right angles to the position of the mandrel shown in Figs. 1 and 2.

Fig. 6 is an end elevation of the inner end of the mandrel with the compression nut removed.

Referring to the drawings, wherein similar reference characters denote corresponding parts throughout the several figures, 1 denotes the mandrel provided with the central bore 2 extending longitudinally therethrough from end to end. 1 The mandrel 1 is provided with an enlarged portion 3 upon which are formed screw threads tand with a cone shaped end 5. Extending radially from the bore 2, through the enlarged por- "tion 3 of the mandrel 1, are the slots 6, preferably three in number, whereby the enlarged body portion 3 of the mandrel 1 consists of the three flexible gripping prongs 7 for gripping the dental instrument (not shown) which is projected through the bore 2 from its inner end and its operating end extending for a distance beyond the cone shaped end 5.

To cause the flexible prongs 7 ,to grip the instrument or tool Within the bore 2, the nut 8 is provided, having internal threads 9 for engaging the threads 4: of the mandrel 1 and also an enlarged milled or knurled head 10 whereby to turn the nut 8 upon the threads 4. Upon the nut 8 is formed the hollow frusto-conical sleeve 11, so that when the nut 8 is screwed inward upon the threads 4: of the mandrel 1, the inner inclined wall of the sleeve 11 will ride upwardly upon the inclined surfaces of the prongs 7, and force the prongs inwardly to clamp the tool.

To attach the inner end of the mandrel 1 to the hand piece of a dental engine, which hand piece may be in the form of a straight or angle hand piece, the inner end of the mandrel 1 is formed with the annular groove 12 providing the head 13, which head 13 and the adjacent portion of the mandrel 1 are longitudinally cut away to provide the flat base 14 and the shoulder 15 whereby to secure this end of the mandrel 1 within a corresponding socket formed in the operating mechanism carried by the hand piece of the dental engine.

From the foregoing it will clearly be seen that I have produced a device which is capable of being readily attached to or detached from the operating mechanisms carried by the hand piece of a dental engine,

which hand piece, may be of the direct or straight type or which may be of any angle type, and that. by providing this mandrelwith its central longitudinal bore therethrough a dental tool may be secured upon the mandrel With any desired portion of its operating end projecting at any desired distance from the end of the mandrel, so that by adjusting the tool in the mandrel any desired length of tool may be attained to accommodate the same to the various uses and positions for operating upon a tooth and which tool may be directed in any desired direction with relation to the tooth being operated upon. Furthermore, in providing this mandrel, a tool can be suiiiciently rigidly secured in the mandrel for ordinary purposes, and at the same time shouldthe tool be subjected to such excessive strains is capable of sufficient rotary movement Within the mandrel as to prevent breaking.

WVhile I have herein disclosed one form of my invention I may resort to variations and modifications in the construction of the various parts thereof to meet the exigencies of a given case Without departing from the spirit of the invention as claimed.

Having described my invention, What ,1

claim as new and desire to secure by Let.- ters Patent, is

The mandrel herein described provided with a central bore extending longitudinally therethroughfrom end to end and having an enlarged, externally threaded portion terminating in a conical end, the enlarged portion, including the conical end, being radially slotted, a sleeve nut having a threaded bore to fit upon the threads of the mandrel with its bore reduced from the screw-threaded portion to its outer end forming said outer end into a frusto-conical sleeve to bear on the split conical outer end of the mandrel, the longitudinal bore being adapted to receive a tool at its inner end to be projected out beyond its outer end andgripped by the radially slotted head, and-means at the inner end of the mandrel to secure it to the hand piece of a dentalengine.

In testimony whereof I have signed my name to this specification in the presence of tWo subscribing Witnesses.

ROY L. SPAULDING.

l/Vitnessesz V a C. A. SPAULDING, M. M., DIXON.

Copies of this patent may be obtained for five centsieach, by addressing the Commissioner of Patents Washington, D. C. i 

